This invention relates to evaporators used with cooling systems for cooling the spaces in the bodies of motor vehicles, and more particularly to an evaporator of the type which has an expansion valve mounted in the evaporator to provide a unitary structure.
In cooling systems of the prior art intended for the aforementioned use, the expansion valve is mounted in a pipe connected to the evaporator, and the expansion valve and the evaporator are mounted separately. This results in the evaporator and the expansion valve occupying a considerably large space. Also, if the expansion valve is supported by a pipe, then violent vibrations of the motor vehicles are directly transmitted to the expansion valve and render unstable the control effected by the expansion valve. Moreover, a torque produced by the weight of the expansion valve acts on connections between the pipe and expansion valve and the pipe and evaporator, thereby causing crack formation and a leaking of the refrigerant through the cracks. Since the cooling systems for cooling the spaces in the bodies of motor vehicles are used under severe conditions of a high thermal load, it is necessary to use a charge of refrigerant of a greater quantity than the charge of refrigerant used in ordinary space coolers or refrigerating apparatus. To this end, an evaporator used with a motor vehicle cooling system includes a plurality of cooling units connected in parallel with one another, and a refrigerant is distributed to the cooling units through a plurality of distributor pipes from a distributor mounted at the end of a pipe connected to the posterior stage of an expansion valve. As a result, the piping around the evaporator is complex and a difficulty is experienced in efficiently performing a piping work. In addition, the presence of many connections reduces the productivity of the cooling systems and causes an increase in the incidence of accidents involving leaking of the refrigerant. Thus the evaporator becomes low in reliability.
In U.S. application Ser. No. 743,492 filed on Nov. 19, 1976 under the title "EVAPORATOR" now U.S. Pat. No. 4,114,397, a proposal is made to use a side plate of the evaporator and two cover plates provided on the side plate in airtight relation to form refrigerant distributing passages, an expansion valve housing, a refrigerant collecting section and U-bend sections for the purpose of simplifying the arrangement of pipes. Japanese Patent Publication No. 26334/77 entitled "EVAPORATOR FOR COOLING SYSTEM" filed on Sept. 6, 1972 discloses art which is similar to the art described above.
The present invention relates to improvements in the prior application or prior art.